I injected fina into my bicep and there was no pain. Just don't go to deep and inject slow. 40 to 60 seconds per cc, but I don't advise putting more than 1cc in your bi's. I used a 25g needle 1 inch but I only put it in 3/4 of the way.
I didn't see any difference with site injections and results but again, I only did this with fina. I heard winny works well with site injections though.
Good luck!
Aikido
i take 1/2 cc in each tri on day then switch to each bicep the next day. i have noticed good growth in both, but esspecially my triceps. i use 25g 1 inch needle. i stick that sucker all the way in.
i inject the bicep in the upper other head, lower outer head, upper inner head, etc.